The invention relates to a system for embossing paper, such as greeting cards, and more particularly relates to an embossing system having an improved flexible counter for supporting a sheet of paper for pressing by a contoured die.
Embossing systems are used to form an embossment or decoratively raised area on a sheet of paper or cardboard. Such an embossment may serve as a decorative feature on a greeting card, business card, or the like. Conventional embossing systems include matable male and female dies contoured in the shape of the desired embossment. With a sheet (e.g., paper) disposed between the two dies, the male and female dies are pressed together in complementary engagement with each other. The paper is thereby deformed to have an embossment matching the contour of the dies.
In an embossing system with mated dies, expenses are incurred for making both the male and female dies. Additionally, such a system requires regular attention to maintain precise die alignment for repeated mating engagement.
The present invention provides improved embossing performance in a system for embossing areas on greeting card material, paper or cardboard products or other items. A flexible counter is provided to support the material being embossed by opposing pressure against a contoured die. The flexible counter has a resilient mat which resides in a fixed bolster. According to an embodiment of the invention, a resilient seal or bumper is provided peripherally around upper sides of the flexible mat to contain the counter during compression between the dies. The bumper is made of a material that is more rigid than the mat, acting to xe2x80x9csealxe2x80x9d flow behavior of the softer mat during compression. In other words, the bumper limits the lateral deformation and stretching of the mat, thereby preventing tearing of the embossed paper and optimizing embossing performance.
According to one aspect of the invention, the bolster has a sidewall secured to a table around a periphery of the mat, and the bumper surrounds an upper portion of the mat, fitting between the mat and the sidewall. For example, in an embodiment, the sidewall includes a channel to accommodate the bumper. The bumper resides, in a recessed fashion, in the channel, having an inner surface supported against the mat. The mat and bumper project a distance above the sidewall.
In an embodiment, the embossing system includes one or more plate-like shim that fits on the table under the mat. Advantageously, the shim permits use of a mat having a thickness dimension less than a depth from the upper edge of the bumper to the table. This enables the mat to be made of a variety of materials which may come in various stock thicknesses, thereby reducing cost.
Various embodiments of the invention provide multiple side-by-side bolsters for simultaneously embossing multiple panels of a sheet. For example, in an embodiment, the table can accommodate the installation of respective sidewalls, mats, and bumpers in one, two, three or more panel configurations as needed to suit a particular embossing job.
In an embodiment, the bumper is unitarily formed in a rectangular shape. In another embodiment, the bumper includes a plurality of strips, each of the strips fitting along a respective side of the rectangular mat. Together, the assembled strips extend around the periphery of the upper portion of the mat.
Embodiments of the invention include additional features found to enhance performance. For example, a friction-reducing film, such as a urethane or mylar film, may be positioned over the mat to separate the mat from the sheet. The friction-reducing film reduces damage to the sheet and aids in removing the sheet from the counter after embossing. The embossing system can include a frame sized to fit externally around a periphery of the sidewalls, and at least one of the edges of the sheet are secured to the frame. In an embodiment, two opposite sides of the sheet are clipped to respective sides of the frame using U-shaped clips. The frame is preferably constructed of steel or some other relatively heavy material so that the weight of the frame holds the film taut across the mat. In an automatic sheet-feeding environment, the sheet is clipped at ends along a feeding direction of the sheets.
An advantage of the present invention is that it provides reliable embossing performance while minimizing damage to the material being embossed.
Another advantage of the present invention is that it permits embossing with only a single contoured die, eliminating a need for a mated die, reducing material expenses. The invention permits the use of either a male or female contoured die.
A related advantage of the present invention is that it eliminates a need to maintain precise die alignment, reducing maintenance effort and associated down time of the system.
A further advantage of the invention is to provide a flexible counter with improved wear characteristics.
Additional features and advantages of the invention are described in, and will be apparent from, the disclosure herein.